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AuthorOmidvarnia, Amir
AuthorAzemi, Ghasem
AuthorBoashash, Boualem
AuthorOtoole, John M.
AuthorColditz, Paul B.
AuthorVanhatalo, Sampsa
Available date2016-03-24T13:39:02Z
Publication Date2014-03
Publication NameIEEE Transactions on Biomedical Engineering
CitationA. Omidvarnia, G. Azemi, B. Boashash, J. M. O'Toole, P. B. Colditz and S. Vanhatalo, "Measuring Time-Varying Information Flow in Scalp EEG Signals: Orthogonalized Partial Directed Coherence," in IEEE Transactions on Biomedical Engineering, vol. 61, no. 3, pp. 680-693, March 2014.
ISSN0018-9294
URIhttp://dx.doi.org/10.1109/TBME.2013.2286394
URIhttp://hdl.handle.net/10576/4259
AbstractThis study aimed to develop a time-frequency method for measuring directional interactions over time and frequency from scalp-recorded electroencephalographic (EEG) signals in a way that is less affected by volume conduction and amplitude scaling. We modified the time-varying generalized partial directed coherence (tv-gPDC) method, by orthogonalization of the strictly causal multivariate autoregressive model coefficients, to minimize the effect of mutual sources. The novel measure, generalized orthogonalized PDC (gOPDC), was tested first using two simulated models with feature dimensions relevant to EEG activities. We then used the method for assessing event-related directional information flow from flash-evoked responses in neonatal EEG. For testing statistical significance of the findings, we followed a thresholding procedure driven by baseline periods in the same EEG activity. The results suggest that the gOPDC method 1) is able to remove common components akin to volume conduction effect in the scalp EEG, 2) handles the potential challenge with different amplitude scaling within multichannel signals, and 3) can detect directed information flow within a subsecond time scale in nonstationary multichannel EEG datasets. This method holds promise for estimating directed interactions between scalp EEG channels that are commonly affected by the confounding impact of mutual cortical sources.
SponsorQatar National Research Fund under its National Priorities Research Program award number NPRP 09-465-2-174. European Community's Seventh Framework Program European Community FP7-PEOPLE-2009-IOF under Grant 254235.
Languageen
PublisherIEEE
SubjectBrain networks
Subjectconnectivity analysis
Subjectdirected coherence
SubjectEEG
Subjectmultivariate autoregressive modeling
Subjectvolume conduction
TitleMeasuring time-varying information flow in scalp EEG signals: Orthogonalized partial directed coherence
TypeArticle
Pagination680-693
Issue Number3
Volume Number61


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